It has throttle body fuel injection which the fuel mixture is controlled by a computer.
If I were to start shooting parts at this Blazer I would put a new O2 sensor in it.
If you don't want to guess, find somebody with a OBD I scanner software to look at the serial data. unfortunately that also means a PAT(PROFESSIONAL AUTO TECH) that can understand what the data means.

the only code that came up was map sensor and it all check out ok I replaced o2 sensor tody still the only thing I found puzzling was where they line from the fuel vapor canister goes into they intake on the carp body nothing change when I took it off to check it.

The purge system is fed at the throttle body. It goes from the throttle body to the purge control solenoid then to the canister.
If you had a scanner that will pull codes what did the serial data look like?